Thermostat



Sept. 22, 1931. H. J. BLAKESLEE THERMOSTAT Filed Sept. 3, 1929 Patented Sept. 22, 1931 I UNITED STATES PATENT OFFICE HENRY .T. BLAKESLEE, OI MABLBORO, CONNECTICUT TEEBMOSTAT Application filed September 3, 1929. Serial No. 389,898.

This invention relates to a thermostat the post 11, and a circuit wire 14 may be elecwhich is particularly adapted for controltrically connected with the plate 12, preferling the action of heat regulating means but ably by means of a lead 15. A circuit wire 16 which is also very serviceable for use with may be electrically connected with the axle 7 other apparatus designed to be regulated acpreferably by means of a lead 17. cording to temperature. Rotatably supported by the walls 3 and 4' The object of the invention is the produc- 1s a spindle 18 fastened to which is a disk or tion of a thermostat which is cheap to manucylinder 19 that is provided with suitable facture, easy to adjust, and simple to setto graduations and that in the preferred form obtain results at the desired temperatures. extends outward through an opening in the The embodiment of the invention illustratcasing cover. Secured to the spindle or to ed has a case'enclosing in a strip of thermothe disk is a cam 20. An arm 21 is fastened static responsive metal that has a normally to the axle 7. This arm may be adjustably fixed end electrically connected with a cirsecured by means of a screw 22, and one end cuit terminal and a free end which projects extends into engagement. with the cam 20 between contacts that are electrically conwhile the other end is engaged by a spring nected with other circuit terminals. The 23 which holds the arm'in engagement with fixed end of the thermal strip is secured to a the cam. When thearm is once adjusted by rotatably mounted axle to which is fastened the makers of the device it requires no fur- I an arm that extends to and is held by spring ther attention. a

tension in engagement with a cam on a spin- By turning the disk the cam bearing upon dle that has a graduated disk or cylinder the arm turns the axle to which the inner end which projects through an opening in the of the coiled thermostatic strip is fastened. c asing cover; By turning the disk the free In use the disk, which extends through the end may be adjusted between the contacts so cover and is the only active part that is exthat it will open and close the required cirposed, is indexed to the desired degree of cuits, asthe temperature changes, in order to temperature tobe retained, at which degree efiect the desired action of the apparatus or the finger will extend between but out of enmeans connected with the circuits. gagement with the circuit contacts 9 and 10.

In the accompanying drawings Fig. 1 Upon a rise in temperature the action of the shows a front view of the article. Fig. 2 is thermostatic strip causes the finger to engage 'a plan with the casing cover removed. Fig. with one circuit contact and upon a drop in 3 is a side elevation with the cover in section. temperature the strip causes the finger to re- Fig. 4 'is an end elevation with the cover in turn to neutral position or to engage the other 1 section. circuit contact should the drop be suflicient.

The base 1 and the cover 2 may bemade of This device is cheap to manufacture and is any suitable insulating material. The cover attractive in appearance, the only portion of may be omitted if desired. Extending upthe active mechanism shown being the gradu- 1 ward from the base are walls, 3 and 4 which ated disk which is exposed through the openare preferably formed integral with the base. ing in the cover and which is simple to turn The inner end 5 of a coiled thermal strip 6 with the thumb or finger for setting so that is secured to a metallic axle 7 which is rothe device will act for the purpose of properly tatably supported by thewalls 3 and 4. Fasshifting the circuits to maintain the required tened to the free end of the thermal strip temperature. With the thermo-responsive shown is a finger 8, which extends between element mounted on an axis that is parallel contacts 9 and 10, the former being threaded to the plane of, the base so said element has into the top of a post 11, and the latter being its movement perpendicular to the plane of threaded into theconducting plate 12 that is the base, there is a saving of space which is fastened to the top of the wall 4. A circuit advantageous when two or more are located wire 13 may be electrically connected with side by side.

on the base and electrically connected with a circuit terminal, a coiled thermostatic strip having one end attached to said axle and its other end extending between circuit contacts, an armadjustably fastened to said axle, a rotatably mounted graduated disk projecting through the casing, and a cam rotatable with I said'disk and engaging said arm, whereby the normal position of the thermostatic strip may be regulated by adjusting the arm with relation to the axle and the action of the thermostatic strip may be varied by rotating said disk and cam.

2. A thermostat comprising a base and an enclosing casing, an axle rotatably mounted transversely of the base, a coiled thermostatic strip having one end attached to said axle and its other end extending longitudinally of the base between circuit contacts, an arm adjustably fastened to and extending radially of said axle, a disk projecting through the casing and mounted to rotate on an axis transverse of the base, and a cam rotatable with said disk and engaging said arm, whereby the normal position of the thermostatic strip may be regulated by adjusting the arm with relation to said axle and the action of the thermostatic strip may be varied by rotating said disk and cam.

HENRY J. BLAKESLEE. 

